Valve-gear.



'No. 855,654. PATENTED JUNE 4, 1907.

J. MoDONALD. VALVE GEAR.

APPLIOATION FILED JUNE 30, 1906.

INVENTOR- W1 TNESSES:

Y ,1 W A TTORNE Y5 UNITED STATES PATENT QFFTQE.

JOHN lWloDONALD, OF BLAIR, NEBRASKA, ASSIGNOR OF ONE-HALF TO PAUL HERPOLSHEIMER, OF SEWARD, NEBRASKA.

VALVE- Specification of Letters Patent.

GEAR.

Patented June 4, 1907.

Application filed June 30,1906. Serial No. 324,213.

To all whom it may concern:

Be it known that I, JOHN MoDoNALD, a citizen of the United States, residing at Blair, in the county of Washington and State of Nebraska, have invented a new and useful Valve-Gear, of which the following is a specification.

This invention relates to valve gears for steam and other engines, and more particularly to reversible valve gears of that class in which a rocker is included between the eccentric and valve to impart motion to the latter, such as is typified by what is commercially known as the Wolf valve gear. While the invention has for certain of its objects to improve the construction and operation of this particular valve gear, the improvements are not necessarily limited thereto.

One of the objects of the invention is to provide an improved valve gear so designed as to permit of the equalizing of the lead and cut-off, and also to enable more leads and an earlier cut-off to be obtained.

A further object is to provide a mechanism of this character that is capable of being used as an attachment or an auxiliary part for certain standard valve gears that can be readily applied with little or no alteration.

Another object is the employment of means whereby the valve can be set while the engine is in operation.

With these objects in view, and others, as

will appear as the nature of the invention is better understood, the invention comprises the various novel features of construction and arrangement of parts, hereinafter fully described, and set forth with particularity in the claims appended hereto.

In the accompanying drawing, which illustrates one of the embodiments of the invention, Figure 1 is a side elevation of a Wolf valve gear with the invention applied thereto. Fig. 2 is a sectional view of the oscillating eccentric connected with the rocker arm of the valve gear, taken on line 2-2 of Fig. 1. Figs. 3 and 4 are detail perspective views, respectively, of the oscillating eccentric and of the means for connecting the pitman which shifts the eccentric and the reversing block guide.

Corresponding parts in the several figures are indicated throughout by similar characl latter being threaded at its end and fitted l with nuts 22 bearing against the bottom leg ters of reference.

Referring to the drawing, 1 represents the main shaft of an engine, or a secondary shaft driven at the required speed, and carried thereby is an eccentric 2. Extending upwardly from the strap 3 of the eccentric is an arm 4 that is provided at its upper end with a slide block 5 arranged in the reversing block guide 6. The shaft 1 is suitably supported in bearings on the frame, or other suitable part of the engine, as will be readily understood. Motion is imparted from the eccentric arm 4 to the valve stem, indicated at 6 by means of an eccentric rod 7 fulcrumed or otherwise secured at 8 to the rocker 9 thatis also suitably supported on the engine structure. For reversing the engine, or changing the speed thereof, a reversing mechanism is employed comprising a notched segment 10, a hand lever 11 having the usual latch 12, and

i a connecting rod 13 extending from the lever to the guide 6.

The mechanism above described represents well known principles of construction commonly employed in steam engineering practice, and I have elected to illustrate my invention as applied to this type of valve ear. g Arranged at one side of the rocker 9 is an eccentric carrying arm 14 that is bolted to the arm or rocker adjacent the free end thereof by means of the same bolt, 8, that connects the eccentric rod 7 with the rocker. The eccentric is indicated at 15 and is preferably cast, forged, or otherwise formed integral with the arm 14. The upper end of the arm 14 is connected with a pitman 16 at one end thereof, which pitman is adjustably connected with the reversing block guide 6, so that an oscillatory motion is imparted to the arm 14 by the rocking of the guide. Means for adjustably connecting the pitman to the guide comprises a plate 17 that is angular in cross section and has one of its sides provided with a plurality of suitably spaced openings 18, and by the other portion it is bolted or otherwise secured to the guide. An L-shaped link 19 is interposed between the angular plate and adjacent end of the pitman, and it is provided at one end with an eye 20 for receiving a bolt 21 whereby the link is connected to the plate 17. The bottom leg of the L-shaped link is provided with an aperture through which the pitman extends, the

of the L-link for clamping the pitman and link together in an adjustable manner. Instead of the eccentric rod 7 being connected directly with the rocker, as is usually the custom, the present improvements necessitate an eccentric strap 23 that engages around the eccentric 15, and the ends of the eccentric rod 7 is threaded so as to screw into the tapped boss 24011 the eccentric strap and is held therein by a clamping nut 25. The end of the oscillating arm 14 is slightly larger than the diameter of the eccentric, so as to form a rim 26 around the latter, which rim, in connection with the flat surface of the rocker 9, permits of a flat surface strap being employed. That is to say, that no retaining means, such as a tongue and groove, is necessary between the eccentric and its strap, for the reason that the flange 26 of the oscillating arm 14 and the surfacevof the rocker 9 retain the eccentric strap 23 in position. The valve stem 6 is reciprocated by the eccentric rod and rocker in the usual manner, but at the same time these parts are actuating the valve stem, the oscilliating arm 14 imparts motion to the rocker through the eccentric 15. The eccentric does not increase the length of stroke of the rocker, since that is limited by the eccentric rod 7. The effect ofthe eccentric 15 is to give the rocker a somewhat quicker movement, thereby causing the valve to travel faster than is possible where the eccentric is connected directly to the rocker. As the reversing block guide oscillates simultaneously with the operation of the eccentric 2, it is readily understood that the rocker actuating eccentric 15 is active during the same period that the eccentric rod is operating, and, furthermore, when the eccentric is rocking the rocker toward the right, the pitman 16 is simultaneously rocking the arm 14 to the right, so that the rate of movement of the valve stem 6 is the result of the combined movement of the rod 7 and eccentric 15.

As shown in Fig. 1, the eccentric 2 of the engine is in a position corresponding to the position of the engine shaft on one of its dead centers, and the eccentric shifting mechanism is adjusted so as to shift the eccentric 15 to its maximum extent. Should the throw of the eccentric be excessive, it is merely necessary to loosen the clamping nuts on the end of the pitman 16 far enough to permit of the L-link being adjusted to the next, or one of the lower, holes in the angle plate 17, this being done preferably without moving the pitman. After the L-link is adjusted, the clamping nuts on the pitman are then reset. After this is done, the uide 6 is rocked back and forth by the hand lever 11 in order to see that the lead of the valve in both directions is equal and set the proper amount.

It will be manifest from the foregoing description that the improvements are capable of the various results set forth and readily permit of the speed of the engine and its direction of rotation being controlled by the hand lever 11 in the usual manner.

Ithas been found in practice that an engine equipped with the invention does not have to be shut down in order to adjust the set of the valve, since by mere manipulation of the clamping nuts on the pitman 16, the set of the valve can be properly obtained.

I have described the principle of operation of the invention, together with the apparatus which I now consider to be the best embodiment thereof, but I desire to have it understood that the apparatus shown is merely illustrative, and that various changes and modifications in the scope of the invention may be resorted to, when desired.

hat is claimed is 1. In a valve gear, the combination of a valve rod, a rocker, a connection between the rod and the free end of the rocker, an oscillating arm pivoted thereon at a point adjacent its free end, means for oscillating the arm, an eccentric rod for oscillating the rocker, means between the eccentric rod and rocker and connected with the arm for accelerating the movement of the valve rod, and an eccentric for actuating the eccentric rod.

2. In a valve gear, the combination of a valve rod, a rocker connected therewith and having a stationary center of oscillation, an eccentric, an eccentric rod, an adjustable member for controlling the stroke of the cocentric rod, an eccentric between the eccentric rod and rocker and moving with the latter, and a connection between the member and eccentric last mentioned. arranged to oscillate the eccentric independently of the rocker to .ary the movement of the valve rod.

3. In a valve gear, the combination of a reciprocating valve rod, a rocking member connected therewith, an eccentric, an eccentric rod between the eccentric and member for actuating the latter, an adjustable oscillating guide for controlling the stroke of the eccentric rod, and means cooperating with the eccentric rod for moving the member, said means including an adjustable connection uniting the guide with the member and arranged to transmit motion from the former to the latter.

4. In a valve gear, the combination of a reciprocating member, an eccentric, an eccentric rod for actuating the member, an adjustable guide for controlling the stroke of the eccentric rod, and. means operating simultaneously with the eccentric rod for moving the member, said means comprising an angle iron mounted on the guide, a link adjustably connected therewith, a pitman adjustably connected with the link at one end, and an arm connected with the opposite end of the pitman and with the eccentric rod and Inem.

ber ior actuating the latter in conjunction l with the eccentric rod.

5. In a valve gear, the combination of a reciprocating member, a rocker connected therewith, an actuating rod for the rocker, means for controlling the length of stroke of the rod, an eccentric device between the eccentric rod and rocker, and means for shifting the eccentric with respect to the rocker, said means comprising an adjustable connection between the guide and eccentric.

6. In a valve gear, the combination of a reciprocating member, a rocker connected therewith, an actuating rod for the rocker, means for controlling the length of stroke of the rod, an eccentric device between the eccentric rod and rocker, and means for shifting the eccentric with respect to the rocker, said means comprising a pitman connected with the eccentric, and a device for adjustably connecting the pitman with the guide.

7. In a valve gear, the combination of a reciprocating member, a rocker connected therewith, an actuating rod for the rocker, means for controlling the length of stroke of the rod, an eccentric device between the eccentric rod and rocker, and me ans for shifting the eccentric with respect to the rocker, the latter comprising an arm for the eccentric, a i pitman connected with the arm, an Lshaped l link adjustably connected with the pitman, and a device adjustably connecting the link with the guide.

8. In a valve gear, the combination of a valve rod, a rocker arm connected therewith, an eccentric mounted for rotation, an eccentric rod connected therewith, a guide for controlling the stroke of the eccentric rod, a mechanism for controlling the guide, an oscillatory eccentric between the eccentric ro d and rocker, a pitman extending substantially parallel with the eccentric rod, means for connecting the pitman with the oscillating eccentric, and means for adjustably connecting the pitman with the guide.

9. In a valve gear, the combination of a valve rod, a rocker, an eccentric rod for actuating the rocker, a strap thereon, an eccentric for the strap, an oscillating arm connected with the eccentric and pivoted on the rocker to oscillate therewith and independently thereof, said rocker and arm forming the sole means for holding the strap on the eccentric, and means for actuating the arm.

10. In a valve gear, the combination of a valve rod, a rocker for reciprocating the same, a reciprocating rod, an arm mounted on the rocker to move therewith, an eccentric disposed between the arm and rocker movable With the arm, a strap connected with the reciprocating rod which is held in position on the rocker, and means foroscillating the arm independently of the rocker and simultaneously with the oscillations of the latter.

In testimony that I claim the foregoing as my own, I have hereto afliXed my signature in the presence of two witnesses.

JOHN MCDONALD.

Witnesses:

\VM. J. LAS, J. F. WM. LADWIG.

eccentric by the arm and 

